/**
 * Copyright (c) 2005-2012 springside.org.cn
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 */
package com.xxg.util;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.StringEscapeUtils;
import org.apache.commons.lang3.Validate;
import org.springframework.util.Assert;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.security.MessageDigest;

/**
 * @ClassName: Encodes
 * @Description 封装各种格式的编码解码工具类.
 * @Author huikai
 * @Date 2019-07-18 11:10:56
 * 1.Commons-Codec的 hex/base64 编码
 * 2.自行编写的，将long进行base62编码以缩短其长度
 * 3.Commons-Lang的xml/html escape
 * 4.JDK提供的URLEncoder
 */
public class Encodes {
    private static final String ALPHABET = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    private static final String DEFAULT_URL_ENCODING = "UTF-8";
    private static String ALPHANUMERIC_STR;

    static {
        String numberStr = "0123456789";
        String aphaStr = "abcdefghijklmnopqrstuvwxyz";
        ALPHANUMERIC_STR = numberStr + aphaStr + aphaStr.toUpperCase();
    }

    private Encodes() {
    }

    /**
     * Hex编码, byte[]->String.
     */
    public static String encodeHex(byte[] input) {
        return Hex.encodeHexString(input);
    }

    /**
     * Hex解码, String->byte[].
     */
    public static byte[] decodeHex(String input) {
        try {
            return Hex.decodeHex(input.toCharArray());
        } catch (DecoderException e) {
            throw new IllegalStateException("Hex Decoder exception", e);
        }
    }

    /**
     * Base64编码, byte[]->String.
     */
    public static String encodeBase64(byte[] input) {
        return Base64.encodeBase64String(input);
    }

    /**
     * Base64编码, URL安全(将Base64中的URL非法字符'+'和'/'转为'-'和'_', 见RFC3548).
     */
    public static String encodeUrlSafeBase64(byte[] input) {
        return Base64.encodeBase64URLSafeString(input);
    }

    /**
     * Base64解码, String->byte[].
     */
    public static byte[] decodeBase64(String input) {
        return Base64.decodeBase64(input);
    }

    /**
     * Base62(0_9A_Za_z)编码数字, long->String.
     */
    public static String encodeBase62(long num) {
        return alphabetEncode(num, 62);
    }

    /**
     * Base62(0_9A_Za_z)解码数字, String->long.
     */
    public static long decodeBase62(String str) {
        return alphabetDecode(str, 62);
    }

    private static String alphabetEncode(long num, int base) {
        num = Math.abs(num);
        StringBuilder sb = new StringBuilder();
        for (; num > 0; num /= base) {
            sb.append(ALPHABET.charAt((int) (num % base)));
        }

        return sb.toString();
    }

    private static long alphabetDecode(String str, int base) {
        Validate.notBlank(str);

        long result = 0;
        for (int i = 0; i < str.length(); i++) {
            result += ALPHABET.indexOf(str.charAt(i)) * Math.pow(base, i);
        }

        return result;
    }

    /**
     * Html 转码.
     */
    public static String escapeHtml(String html) {
        return StringEscapeUtils.escapeHtml4(html);
    }

    /**
     * Html 解码.
     */
    public static String unescapeHtml(String htmlEscaped) {
        return StringEscapeUtils.unescapeHtml4(htmlEscaped);
    }

    /**
     * Xml 转码.
     */
    public static String escapeXml(String xml) {
        return StringEscapeUtils.escapeXml(xml);
    }

    /**
     * Xml 解码.
     */
    public static String unescapeXml(String xmlEscaped) {
        return StringEscapeUtils.unescapeXml(xmlEscaped);
    }

    /**
     * Csv 转码.
     */
    public static String escapeCsv(String csv) {
        return StringEscapeUtils.escapeCsv(csv);
    }

    /**
     * Csv 解码.
     */
    public static String unescapeCsv(String csvEscaped) {
        return StringEscapeUtils.unescapeCsv(csvEscaped);
    }

    /**
     * URL 编码, Encode默认为UTF-8.
     */
    public static String urlEncode(String part) {
        try {
            return URLEncoder.encode(part, DEFAULT_URL_ENCODING);
        } catch (UnsupportedEncodingException e) {
            throw Exceptions.unchecked(e);
        }
    }

    /**
     * URL 解码, Encode默认为UTF-8.
     */
    public static String urlDecode(String part) {

        try {
            return URLDecoder.decode(part, DEFAULT_URL_ENCODING);
        } catch (UnsupportedEncodingException e) {
            throw Exceptions.unchecked(e);
        }
    }

    /**
     * SHA-1 加密
     *
     * @param srcStr
     * @return
     */
    public static String getSHADigest(String srcStr) {
        return getDigest(srcStr, "SHA-1");
    }

    /**
     * MD5 加密
     *
     * @param srcStr
     * @return
     */
    public static String getMD5Digest(String srcStr) {
        return getDigest(srcStr, "MD5");
    }

    /**
     * 获取特定长度的机器码
     *
     * @param length
     * @return
     */
    public static String getRandomStr(int length) {
        int srcStrLen = ALPHANUMERIC_STR.length();
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < length; ++i) {
            int maxnum = (int) (Math.random() * 1000.0D);
            int result = maxnum % srcStrLen;
            char temp = ALPHANUMERIC_STR.charAt(result);
            sb.append(temp);
        }
        return sb.toString();
    }

    /**
     * 加密方法
     *
     * @param srcStr
     * @param alg
     * @return
     */
    @SuppressWarnings("deprecation")
    private static String getDigest(String srcStr, String alg) {
        Assert.notNull(srcStr);
        Assert.notNull(alg);
        try {
            MessageDigest alga = MessageDigest.getInstance(alg);
            alga.update(srcStr.getBytes());
            byte[] digesta = alga.digest();
            return byte2hex(digesta);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * 转码
     *
     * @param b
     * @return
     */
    private static String byte2hex(byte[] b) {
        StringBuffer hs = new StringBuffer();
        String stmp = "";
        for (int n = 0; n < b.length; ++n) {
            stmp = Integer.toHexString(b[n] & 0xFF);
            if (stmp.length() == 1) {
                hs.append("0");
            }
            hs.append(stmp);
        }
        return hs.toString().toUpperCase();
    }

    public static void main(String[] args) {

    }
}
